2.1. Defining Relations

All sessions with SNePS begin by defining the relations (arc labels) that you want to use. (Some relations, for use with node-based inference, are built in; see §7, below, and UM§2.5, UM Ch. 3.) To define a set of relations, evaluate the SNePSUL command define, giving it as arguments the names of the relations (UM§2.5).

Define the relations isa and ako by evaluating:

(define isa ako)

(Note to the reader/user: To get the full benefit from this interactive tutorial, you should

do everything that is in a box like this.

It is also useful to draw the network as you build it; you can then compare your drawing of the network with the information that SNePS gives you. If the Xginseng program (or another graph-drawing program) is working, you can also use it to see a picture of the network; see §6.2.)